kernel + sh: Another stream overhaul

Certain streams can now be opened by name by prefixing the name
with a colon (':'). The only supported named stream at the moment
is :fb, which streams to/from the background framebuffer.

A new syscall called `get_size` was also added, which should be used
instead of `ryfs_get_size`. This new syscall supports getting the size
of streams.

applications/sh/commands/dir.asm

@@ -63,7 +63,7 @@ shell_dir_command_loop:
     cmp r0, 0
     ifz jmp shell_dir_command_failed_to_open_file
     mov r0, shell_dir_command_temp_file_struct
-    call ryfs_get_size
+    call get_size
     call print_decimal_to_terminal
 shell_dir_command_failed_to_open_file:
     ; new line

applications/sh/commands/type.asm

@@ -16,7 +16,7 @@ shell_type_command:
     ifz jmp shell_type_command_file_not_found
 
     mov r0, shell_type_command_file_struct
-    call ryfs_get_size
+    call get_size
     mov r31, r0
 shell_type_command_loop:
     mov r0, 1

applications/sh/launch.asm

@@ -45,7 +45,7 @@ launch_fxf_name_loop_done:
 
     ; allocate memory for the binary
     mov r0, launch_fxf_struct
-    call ryfs_get_size
+    call get_size
     call allocate_memory
     cmp r0, 0
     ifz jmp allocate_error

fox32os.def

@@ -42,6 +42,7 @@ seek:                      jmp [0x00000D14]
 tell:                      jmp [0x00000D18]
 read:                      jmp [0x00000D1C]
 write:                     jmp [0x00000D20]
+get_size:                  jmp [0x00000D24]
 
 ; widget jump table
 draw_widgets_to_window:    jmp [0x00000E10]

kernel/fxf/launch.asm

@@ -33,7 +33,7 @@ launch_fxf_from_disk:
 
     ; allocate memory for the binary
     mov r0, launch_fxf_struct
-    call ryfs_get_size
+    call get_size
     call allocate_memory
     cmp r0, 0
     ifz jmp launch_fxf_from_disk_allocate_error

kernel/main.asm

@@ -65,6 +65,7 @@ jump_table:
     data.32 tell
     data.32 read
     data.32 write
+    data.32 get_size
 
     ; widget jump table
     org.pad 0x00000610
@@ -204,7 +205,7 @@ load_startup_task:
 
     ; allocate memory for the startup file
     mov r0, startup_file_struct
-    call ryfs_get_size
+    call get_size
     call allocate_memory
     cmp r0, 0
     ifz jmp memory_error
@@ -239,7 +240,7 @@ load_startup_task:
     ; we do this by checking to see if the size of startup.cfg is less than or equal to 12 * next_task_id bytes
     inc.8 [next_task_id]
     mov r0, startup_cfg_struct
-    call ryfs_get_size
+    call get_size
     movz.8 r1, [next_task_id]
     mul r1, 12
     cmp r0, r1
@@ -385,9 +386,9 @@ get_os_api_version:
     #include "allocator.asm"
     #include "fxf/fxf.asm"
     #include "task.asm"
+    #include "vfs/vfs.asm"
     #include "widget/widget.asm"
     #include "window/window.asm"
-    #include "vfs.asm"
 
 bottom_bar_str_0: data.strz "FOX"
 bottom_bar_str_1: data.strz "32"

kernel/vfs/fb.asm

@@ -0,0 +1,60 @@
+; framebuffer vfs stream routines
+
+framebuffer_vfs_stream_name: data.strz "fb"
+
+; open a framebuffer stream
+; inputs:
+; r2: file struct: pointer to a blank file struct (stream)
+; outputs:
+; r0: non-zero
+open_stream_fb:
+    push r2
+
+    mov.8 [r2], 0             ; write file_reserved_1
+    inc r2
+    mov.16 [r2], 0            ; write file_reserved_2
+    add r2, 2
+    mov [r2], 0               ; write file_seek_offset
+    add r2, 4
+    mov.8 [r2], 1             ; write file_system_type
+    inc r2
+    mov [r2], fb_stream_read  ; write file_read_call
+    add r2, 4
+    mov [r2], fb_stream_write ; write file_write_call
+    add r2, 4
+    mov [r2], 0x0012C000      ; write file_size
+    add r2, 4
+    mov [r2], 0               ; write file_reserved_3
+    add r2, 4
+    mov [r2], 0               ; write file_reserved_4
+    add r2, 4
+    mov [r2], 0               ; write file_reserved_5
+
+    pop r2
+    mov r0, 1
+    ret
+
+; read a byte from the framebuffer
+; inputs:
+; r0: seek offset
+; outputs:
+; r0: byte
+fb_stream_read:
+    add r0, 0x02000000
+    cmp r0, 0x0212C000
+    ifgteq mov r0, 0x0212BFFF
+    movz.8 r0, [r0]
+    ret
+
+; write a byte to the framebuffer
+; inputs:
+; r0: pointer to source buffer
+; r1: seek offset
+; outputs:
+; none
+fb_stream_write:
+    add r1, 0x02000000
+    cmp r1, 0x0212C000
+    ifgteq mov r1, 0x0212BFFF
+    mov.8 [r1], [r0]
+    ret

kernel/vfs/vfs.asm

@@ -5,6 +5,12 @@
 ;   file_first_sector: 2 bytes
 ;   file_seek_offset:  4 bytes
 ;   file_system_type:  1 byte (0x00 for RYFS)
+;   file_reserved_1:   4 bytes
+;   file_reserved_2:   4 bytes
+;   file_reserved_3:   4 bytes
+;   file_reserved_4:   4 bytes
+;   file_reserved_5:   4 bytes
+;   file_reserved_6:   4 bytes
 
 ; file struct for stream:
 ;   file_reserved_1:  1 byte
@@ -13,19 +19,40 @@
 ;   file_system_type: 1 byte (0x01 for stream)
 ;   file_read_call:   4 bytes
 ;   file_write_call:  4 bytes
+;   file_size:        4 bytes
+;   file_reserved_3:  4 bytes
+;   file_reserved_4:  4 bytes
+;   file_reserved_5:  4 bytes
 
-; open a file from a RYFS-formatted disk
+; open a file from a RYFS-formatted disk, or a named stream
 ; inputs:
-; r0: pointer to file name string (8.3 format, for example "testfile.txt" or "test.txt")
+; r0: pointer to file name string (8.3 format if file, for example "testfile.txt" or "test.txt")
-; r1: disk ID
+; r1: disk ID (ignored if stream)
-; r2: file struct: pointer to a blank file struct
+; r2: file struct: pointer to a blank file struct (8 bytes if file, 16 bytes if stream)
 ; outputs:
-; r0: first file sector, or zero if file wasn't found
+; r0: if file: first file sector, or zero if file wasn't found
+;     if stream: non-zero if stream opened, or zero if not
 open:
+    cmp.8 [r0], ':'
+    ifz jmp open_stream
     call convert_filename
     cmp r0, 0
     ifz ret
     jmp ryfs_open
+open_stream:
+    push r1
+
+    inc r0
+
+    ; fb
+    mov r1, framebuffer_vfs_stream_name
+    call compare_string
+    ifz pop r1
+    ifz jmp open_stream_fb
+
+    pop r1
+    mov r0, 0
+    ret
 
 ; seek specified file to the specified offset
 ; inputs:
@@ -44,13 +71,38 @@ seek:
 tell:
     jmp ryfs_tell
 
+; get the exact size of the specified file
+; inputs:
+; r0: pointer to file struct
+; outputs:
+; r0: size in bytes
+get_size:
+    push r1
+    push r0
+    add r0, 7
+    movz.8 r1, [r0]
+    pop r0
+    cmp.8 r1, 0x00
+    ifz pop r1
+    ifz jmp ryfs_get_size
+    cmp.8 r1, 0x01
+    ifz pop r1
+    ifz jmp stream_get_size
+    pop r1
+    ret
+stream_get_size:
+    add r0, 16
+    mov r0, [r0]
+
+    ret
+
 ; read specified number of bytes into the specified buffer
 ; inputs:
 ; r0: number of bytes to read
 ; r1: pointer to file struct
 ; r2: pointer to destination buffer
 ; outputs:
-; r0: number of bytes left to read (streams can read short)
+; none
 read:
     push r3
     push r1
@@ -66,25 +118,26 @@ read:
     pop r3
     ret
 stream_read:
+    push r0
     push r1
     push r2
-
 stream_read_loop:
     call stream_read_char
-    call yield_task
 
-    cmp.8 [r2], 0
+    push r0
-    ifz jmp stream_read_out
+    push r2
+    call yield_task
+    pop r2
+    pop r0
 
     inc r2
     dec r0
     ifnz jmp stream_read_loop
 
-stream_read_out:
     pop r2
     pop r1
+    pop r0
     ret
-
 stream_read_char:
     push r0
     push r1
@@ -100,6 +153,10 @@ stream_read_char:
     pop r2
     mov.8 [r2], r0
 
+    ; increment the seek offset
+    sub r1, 6
+    inc [r1]
+
     pop r1
     pop r0
     ret
@@ -138,7 +195,6 @@ stream_write_loop:
     pop r2
     pop r31
     ret
-
 stream_write_char:
     push r0
     push r1
@@ -152,6 +208,10 @@ stream_write_char:
     add r3, 10
     call [r3]
 
+    ; increment the seek offset
+    sub r3, 10
+    inc [r3]
+
     pop r3
     pop r1
     pop r0
@@ -239,3 +299,6 @@ convert_filename_fail:
     pop r1
     ret
 convert_filename_output_string: data.fill 0, 12
+
+    ; named streams
+    #include "vfs/fb.asm"